Water-based paint-removing solution

ABSTRACT

Paint residues may be removed from spraying equipment and the like by flushing with aqueous compositions containing alkoxylated aromatic alcohols wherein the aromatic ring moieties of such alcohols do not bear any alkyl substituent containing more than 4 carbon atoms. Preferably, the aqueous compositions also contain an alkanolamine or other base. The alkoxylated aromatic alcohols contain an average of at least about 2 oxyalkylene moieties (preferably, oxyethylene moieties) per molecule.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from provisional application Ser. No.60/259,667, filed Jan. 4, 2001, incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

This invention relates to cleaning paint, whether fresh, dried, and/oraged, from surfaces where such paint is not desired. More particularly,this invention relates to cleaning paint from paint spraying equipment,to a novel water-based solution for accomplishing such cleaning, and toa concentrate from which the solution can be made by dilution with wateronly.

Current commercial practice in the art preponderantly utilizes solutionsthat comprise a component of amines and a component of organic solventgenerally selected from the group consisting of simple alcohols andmonoethers of glycols, most or all with molecules that contain no morethan eight carbon atoms, in order to have sufficient water solubility.The amines used are typically alkanolamines like dimethyl ethanol amine,methyl isopropanol amine, and diethanol amine but are not limited tothis class of amines. Typical solvents used in the solution are alcoholsand glycol ethers, such as n-butanol, ethylene glycol mono butyl ether,diethylene glycol n-butyl ether, triethylene glycol methyl ether,propylene glycol normal butyl ether, dipropylene glycol methyl ether,propylene glycol methyl ether, and propylene glycol normal propyl ether.Typical concentrate formulas consist of 85 to 99% of solvent and 1 to15% of alkanolamine, with the balance water. The concentrates areusually diluted to from 5% to 15%, by weight or volume, in deionizedwater for use as a working water-based paint-removing solution.Operating temperature when using the water-based solution is usally from21 to 55° C.

Many of the constituents of conventional paint removing solutions arelegally classified as “volatile organic compounds”, hereinafter usuallyabbreviated as “VOC”. A major object of this invention is to providepaint flushing solutions and processes that are as technicallysatisfactory for paint flushing as current commercial processes but havesubstantially lower VOC content and/or emissions. Other alternativeand/or concurrent objects will become apparent from the descriptionbelow.

Except in the claims and the operating examples, or where otherwiseexpressly indicated to the contrary, all numerical quantities in thisdescription indicating amounts of material or conditions of reactionand/or use are to be understood as modified by the word “about” indescribing the broadest scope of the invention. Practice within thenumerical limits stated is generally preferred, however. Also,throughout the description and claims, unless expressly stated to thecontrary: percent, “parts of”, and ratio values are by weight; the term“polymer” includes “oligomer”, “copolymer”, “terpolymer”, and the like;the description of a group or class of materials as suitable orpreferred for a given purpose in connection with the invention impliesthat mixtures of any two or more of the members of the group or classare equally suitable or preferred; description of constituents inchemical terms refers to the constituents at the time of addition to anycombination specified in the description, and does not necessarilypreclude chemical interactions among the constituents of a mixture oncemixed; specification of materials in ionic form implies the presence ofsufficient counterions to produce electrical neutrality for thecomposition as a whole, and any counterions thus implicitly specifiedpreferably are selected from among other constituents explicitlyspecified in ionic form, to the extent possible; otherwise suchcounterions may be freely selected, except for avoiding counterions thatact adversely to the objects of the invention; the term “paint” and itsgrammatical variations includes any more specialized types of protectiveexterior coatings that are also known as, for example, lacquer,electropaint, shellac, top coat, base coat, color coat, and the like;and the term “mole” and its variations may be applied to ionic,chemically unstable neutral, or any other chemical species, whetheractual or hypothetical, that is specified by the type(s) of atomspresent and the number of each type of atom included in the unitdefined, as well as to substances with well defined neutral molecules.

BRIEF SUMMARY OF THE INVENTION

The invention provides a method of cleaning paint from non-water-solublesurfaces, especially metal surfaces, comprising contacting the paintwith an aqueous composition comprising a water-soluble alkoxylatedaromatic alcohol such as an ethoxylated phenol or an ethoxylated benzylalcohol which contains an aromatic ring moiety but which does not bearany alkyl substituent having more than 4 carbon atoms. In preferredembodiments, the aqueous composition is additionally comprised of a basesuch as a water-soluble alkanolamine. The aqueous composition ispreferably homogenous and single phase in character.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The present invention is particularly suitable for use in removinguncured water-borne paint from surfaces and the various embodimentsdescribed as preferred herein are preferred with respect to such end-useapplication. However, the invention is also useful for removing curedwater-borne paint as well as solvent-borne paint, although for suchapplications variations from the embodiments described herein aspreferred may be necessary in order to achieve optimum results.

It has been found that aqueous solutions of water-soluble alkoxylatedaromatic alcohols containing oxyalkylene moieties such as oxyethylenebut which do not have relatively long chain alkyl groups substituted onthe aromatic ring are quite effective in removing paint residues fromsurfaces. Preferably, the alkoxylated aromatic alcohol component of thepaint-removing solution contains an average of from about 2 to about 10oxyethylene moieties per molecule.

Th alkoxylated aromatic alcohol preferably is a non-ionic organiccompound comprising, in each molecule:

-   -   (1) an aromatic ring moiety, wherein said aromatic ring moiety        does not bear any alkyl substituent containing more than 4        carbon atoms; and    -   (2) a linear moiety that conforms to the immediately following        general formula (I):        wherein m represents a positive integer of at least 2 and each        of R¹ through R⁴, independently for each and independently from        one to another of the m instances of each of R¹ through R⁴ in        said linear moiety, represents either a covalently bonded        hydrogen atom or a covalently bonded methyl moiety. The        above-mentioned linear moiety is attached to the aromatic ring        moiety, preferably through an ether oxygen alone or through an        oxymethylene (—CH₂—O—) moiety. The end of the linear moiety        which is not attached to the aromatic ring moiety is preferably        hydroxyl-terminated (i.e., an OH group is present at one end of        the linear moiety).

In one embodiment of the invention the water-soluble alkoxylatedaromatic alcohol component is a mixture of compounds corresponding tothe general structure.

wherein m represents a positive integer which is at least about 2 onaverage (more preferably, at least about 3 on average) and independentlyis no more than about 10 on average (more preferably, no more than about5 on average), each of R¹ through R⁴ independently from one to anotherof the m instances of each of R¹ through R⁴ in the same molecule,represents either a covalently bonded hydrogen atom or a covalentlybonded methyl moiety, subject to the proviso that at least about 70number % (more preferably, at least 80 number %; most preferably, atleast about 90 number % of the moieties) indicated by the symbols R¹through R⁴ in said mixture represent hydrogen atoms, Ar is a substitutedor unsubstituted phenyl moiety (“unsubstituted” meaning that there areno substituents on the phenyl ring other than the oxyalkylene moieties),subject to the proviso that Ar contains no alkyl substituent containingmore than 4 carbon atoms (more preferably, Ar contains no alkylsubstituent containing more than 2 carbon atoms; most preferably, Arcontains no alkyl substituent containing more than 1 carbon atom), R⁵ isselected from hydrogen or methyl, and p is 0 or 1.

Representative preferred alkoxylated aromatic alcohols includetriethylene glycol monophenyl ether, tetraethylene glycol monophenylether, pentaethylene glycol monophenyl ether, hexaethylene glycolmonophenyl ether, heptaethylene glycol monophenyl ether, triethyleneglycol monobenzyl ether, tetraethylene glycol monobenzyl ether,pentaethylene glycol monobenzyl ether, hexaethylene glycol monobenzylether, heptaethylene glycol monobenzyl ether, water-soluble ethoxylatesof propylene glycol monophenyl ether (preferably, containing an averageof at least 2 oxyethylene moieties per molecule), and the like andmixtures thereof. Suitable alkoxylated aromatic alcohols are availablefrom commercial sources such as Harcross (T Det P4) and Clariant(ST-8329 and Genapol® BA 04).

Non-exclusive examples of suitable ring moieties for part (1) of thealkoxylated aromatic alcohol molecules as described above are the ringsof benzene and naphthalene. Any of the positions on these rings may besubstituted with halogen or alkyl moieties, and at least one of thepositions on these rings must be substituted with a moiety that includesa linear moiety as described in part (2) above. These linear moietiesare normally produced by condensing at least one alkylene oxide (e.g.,ethylene oxide, propylene oxide) with a suitable compound having atleast one active hydrogen (e.g., phenol, benzyl alcohol), as isgenerally well known in the art. Alkoxylation is preferably carried outunder conditions effective to react an average of at least about two(more preferably, at least about three) moles of alkylene oxide per moleof active hydrogen in the aromatic alcohol.

At least for economy, for the alkoxylated aromatic alcohol component thefollowing preferences apply, each independently of the others, withcombinations of the preferences being still more preferred, the greaterthe number of the following preferences that apply simultaneously:

-   -   there is only one ring moiety in each molecule;    -   at least, with increasing preference in the order given, 50, 70,        80, 90, 95, or 99 number % of the ring moieties are phenyl        rings, optionally substituted but more preferably unsubstituted,        except for any substituent that contains a linear moiety        according to general formula (I);    -   any substituent on a ring moiety, except a substituent that        contains a moiety according to general formula (I), contains not        more than, with increasing preference in the order given, 4, 3,        2, or 1 carbon atoms and not more than, with increasing        preference in the order given, 3, 2, 1, or 0 of any atoms except        carbon and hydrogen atoms;    -   at least, with increasing preference in the order given, 50, 60,        70, 75, 80, 85, 90, 95, or 99 number % of the moieties indicated        by the symbols R¹ through R⁴ in general formula (I) represent        hydrogen atoms;    -   the average number of carbon atoms in the shortest path along        chemical bonds between a carbon atom that is part of a ring        moiety as defined in part (A)(1) above and an oxygen atom that        is either bonded directly to a moiety conforming to general        formula (I) or is itself part of a moiety conforming to general        formula (I) is not more than, with increasing preference in the        order given, 10, 8, 6, 4, 3.0, 2.5, 2.0, 1.5, or 1.0;    -   there is a ratio between the number of carbon atoms in moieties        that conform to the general formula —CH₂—CH₂—O— and the number        of all other carbon atoms in the alkoxylated aromatic alcohol        component that is at least, with increasing preference in the        order given, 0.10:1.00, 0.20:1.00, 0.30:1.00, 0.40:1.00,        0.45:1.00, 0.50:1.00, 0.54:1.00, 0.56:1.00, 0.58:1.00, or        0.60:1.00 and independently preferably is not more than, with        increasing preference in the order given, 2.00:1.00, 1.5:1.00,        1.0:1.00, 0.90:1.00, 0.85:1.00, 0.82:1.00, 0.80:1.00, 0.78:1.00,        0.76:1.00, 0.74:1.00, 0.72:1.00, or 0.70:1.00;    -   where a mixture of alkoxylated aromatic alcohols is used, the        number percent of molecules of the mixture for which the value        of m in general formula (I) has the value of the nearest integer        to the number average value of m for the mixture as a whole is        at least, with increasing preference in the order given, 10, 13,        16, 18, 20, or 22% and independently preferably is not more        than, with increasing preference in the order given, 75, 60, 50,        40, 35, 30, 28, 26, or 24%;    -   the number percent of molecules of a mixture of alkoxylated        aromatic alcohols for which the value of m in general        formula (I) has a value that does not differ by more than 1 from        the nearest integer to the number average value of m for the        mixture as a whole is at least, with increasing preference in        the order given, 30, 35, 40, 45, 50, 54, 57, or 60% and        independently preferably is not more than, with increasing        preference in the order given, 90, 80, 73, 69, 66, 64, or 62%;        and    -   the number percent of molecules of a mixture of alkoxylated        aromatic alcohols for which the value of m in general        formula (I) has a value that does not differ by more than 2 from        the nearest integer to the number average value of m for the        mixture as a whole is at least, with increasing preference in        the order given, 60, 70, 75, 78, 80, 82, or 84% and        independently preferably is not more than, with increasing        preference in the order given, 95, 93, 91, 89, 87, or 85%.

In preferred embodiments of the invention, the alkoxylated aromaticalcohol is used in combination with a water-soluble base (i.e., asubstance capable of rendering the aqueous composition used as a paintremoving solution alkaline). Organic as well as inorganic bases may beemployed, although organic bases are generally preferred. Generallyspeaking, an amount of base is preferably used which is sufficient toprovide a pH in the working paint-removing solution of from about 8 toabout 14 (more preferably, from about 9.5 to about 11.5).

The base component as described above preferably is an alkanolamine andpreferably is selected from alkanolamine molecules that jointly have thefollowing characteristics, each of which is preferred individually andcombinations of which are still more preferred, the greater the numberof individual preferences in the combination:

-   -   the average number of amino nitrogen atoms per molecule is not        more than, with increasing preference in the order given, 5, 3,        2.0, 1.8, 1.6, 1.4, 1.2, or 1.0;    -   the average number of moieties other than hydrogen atoms that        are directly bonded to each amino nitrogen atom is not more        than, with increasing preference in the order given, 2.5, 2.0,        1.7, 1.4, 1.2, or 1.0;    -   the average number of carbon atoms per amino nitrogen atom is        not less than, with increasing preference in the order given,        1.5, 2.0, 2.5, 2.7, or 2.9 and independently preferably is not        more than, with increasing preference in the order given, 10, 8,        6, 5.0, 4.5, 4.0, 3.8, 3.6, 3.4, 3.2, or 3.0;    -   the average number of hydroxyl moieties per amino nitrogen        moiety is at least, with increasing preference in the order        given, 0.2, 0.4, 0.6, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, or        0.98 and independently preferably is not more than, with        increasing preference in the order given, 2.5, 2.0, 1.7, 1.4,        1.2, or 1.02;    -   the percent of total nitrogen atoms that are amino nitrogen        atoms is at least, with increasing preference in the order        given, 50, 60, 70, 80, 90, 95, or 99%; and    -   the percentage of total oxygen atoms that are part of hydroxyl        moieties is at least, with increasing preference in the order        given, 50, 60, 70, 80, 90, 95, or 99%.

The single most preferred substance for the base component is2-aminopropanol-1 (also known as monoisopropanolamine), but othersuitable alkanolamines include dimethylethanolamine, diethanolamine,triethanolamine, triisopropanolamine, monoethanolamine, n-butyldiethanolamine, 2-methylaminoethanol, n-butylaminoethanol,diethylaminoethanol, 2-amino-2-methyl-1-propanol, phenyl diethanolamine,diisopropanolamine and the like. Other water-soluble amines such asalkylamines (e.g., triethylamine) and oxazolidines may also be used.Examples of suitable inorganic bases include alkali metal hydroxides,alkali metal carbonates, alkali metal silicates, alkali metalphosphates, and other basic alkali metal salts. In one embodiment of theinvention, an alkanolamine is used in combination with an alkali metalsilicate such as sodium silicate (preferably, at a silicateconcentration in the working solution of from about 0.001 to about 0.1weight percent).

The ratio by mass of the alkoxylated aromatic alcohol component asdescribed above to the base component as described above in aconcentrate or a working composition according to this inventionpreferably is (where the base is an amine) at least, with increasingpreference in the order given, 1.0:1.00, 2.0:1.00, 3.0:1.00, 4.0:1.00,5.0:1.00, 6.0:1.00, 7.0:1.00, 7.5:1.00, 8.0:1.00, 8.5:1.00 or 8.9:1.00and independently preferably is not more than, with increasingpreference in the order given, 40:1.00, 30:1.00, 25:1.00, 20:1.00,15:1.00, 13:1.00, 11.0:1.00, 10.5:1.00, 10.0:1.00, 9.8:1.00, 9.6:1.00,9.4:1.00, 9.2:1.00, or 9.1:1.00. If a relatively strong inorganic basesuch as an alkali metal hydroxide is used, the preferred alkoxylatedaromatic alcohol:base mass ratio will generally be higher.

The various components of the working water-based, paint-removingsolutions of the present invention and the concentrations of suchcomponents are preferably selected such that the composition has a VOCcontent (as measured by EPA Method 24) of less than about 0.1 lb./gal,preferably less than about 0.08 lb./gal, and most preferably less thanabout 0.06 lb./gal.

In a concentrate composition according to the invention, substantialconcentrations of water are economically disadvantageous, because theyincrease the cost of shipping the active ingredients of the concentratefrom its point of manufacture to its point of use. However, thisdisadvantage is purely economic rather than technical and is thereforeminimal if the concentration of water in a concentrate is not more thanabout 10%. On the other hand, water is usually economically necessary ina working composition for actual paint removal according to theinvention.

Ordinarily, components other than water, alkoxylated aromatic alcoholand base are not needed in a composition according to the invention andin such instances are preferably omitted, at least for economy. However,an additional surfactant may be needed in some instances to improveinitial wetting of the paint to be removed from the substrate surface.The surfactant may be anionic, non-ionic, cationic or amphoteric incharacter, but preferably is a low foaming surfactant or is used incombination with a defoamer to minimize the amount of foam generatedduring use. Examples of suitable surfactants include alkylarylsulfonates such as sodium xylene sulfonate, ethoxylated fatty esters andoils such as MERPOL A (available commercially from E.I. duPont deNemours & Co.), non-ionic fluorocarbon-based surfactants such as ZONYLFSN (available from E.I. duPont de Nemours & Co.), and non-ionicethoxylated alkylphenols such as ethoxylated octylphenol. If the waterused is very “hard”, meaning that it contains substantial concentrationsof calcium and/or magnesium cations, a chelating agent for these ionsmay be needed to prevent unwanted precipitation of scums on the surfacesbeing cleaned. Suitable chelating agents include water-soluble compoundscontaining two or more functional groups such as carboxylic acid groups,phosphoryl groups, amine groups, and/or hydroxyl groups which arearranged in suitable positions in the chelating agent molecule such thatatoms in two or more functional groups are capable of complexing with asinglr calcium and/or magnesium cation. Non-limiting examples ofsuitable chelating agents include EDTA, gluconic acid, citric acid,polyphosphonic acids, and salts thereof. In some instances for removingespecially difficult paints, additional solvent may be needed and may betolerable even if it increases the VOC content of the composition. Theauxiliary solvents are preferably water-soluble and may be selectedfrom, for example, polyalkylene glycols, glycols, glycol ethers, glycolesters, glycol oligomers, aliphatic and aromatic alcohols, ethers,ketones, and the like. Corrosion inhibitors may also be present in thepaint-removing compositions of the present invention.

Small amounts of alkoxylated aromatic alcohols having a relatively lowdegree of alkoxylation (e.g., wherein n in the aforedescribed generalformula is 1) may also be present in the composition, but it ispreferred that such amounts be minimized since such compounds are onlysparingly soluble in water and undesirably increase the VOC content ofthe composition. Also, under at least some conditions, such compoundshave surprisingly been found to be less efficient in removing paint thanthe more highly alkoxylated aromatic alcohols which are the subject ofthe present invention.

In a process according to the invention, contact between the solution asdescribed above and any paint contaminated surface to be cleaned ofpaint may be brought about by any convenient method. Immersion andspraying are the most common methods. If the surface to be cleaned has ashape that can be readily and reasonably uniformly contacted byspraying, this method of contact is generally preferred, because themechanical force of impingement of the sprayed solution aids inefficient paint removal. On the other hand, if the surface to be cleanedhas recesses or other shapes that can not readily be contacted byspraying, immersion (flooding) will generally be preferred. The solutionmay be agitated to help accelerate the rate of paint removal. Bothmethods can, of course be combined and/or varied in ways apparent tothose skilled in the art. The optimum values of active ingredientconcentrations and temperature of the working solution depend to someextent on the method of contact and the impingement force (if any)achieved by the contact. General guidelines for spraying are givenbelow, but in any instance, those skilled in the art will be able todetermine optimum conditions by minimal experimentation.

In a working paint-removing solution, the concentration of thealkoxylated aromatic alcohol component as described above preferably isat least, with increasing preference in the order given, 0.5, 1.0, 1.3,1.6, 1.9, 2.1, 2.3, or 2.5% and independently preferably, at least foreconomy, is not more than, with increasing preference in the ordergiven, 30, 20, 10, 8, 6.0, 5.0, 4.5, or 4.0%. The concentration of thebase component (when one or more water-soluble amines are used as thebase component) preferably is at least, with increasing preference inthe order given, 0.05, 0.1, 0.15, 0.20, 0.25% and independentlypreferably, at least for economy, is not more than with increasingpreference in the order given, 3, 2, 1, or 0.5%. Higher concentrationswithin these preferences are preferred for immersion or low forcespraying, while lower concentrations are satisfactory technically andare more economical for high force spraying.

Spraying pressure will normally range from 1.3 to 8.0 bars absolutepressure. Near the lower end of this range, the temperature of thepaint-removing solution preferably is at least, with increasingpreference in the order given, 15, 20, 25, 30, 40, 50, 55, or 60° C. ifspeed of removal of the paint is important. On the other hand, if thespraying pressure is as much as 2.7 bars, there is no technicaladvantage to a solution temperature greater than 38° C., because thecontact time required is not substantially reduced by highertemperature, while the energy cost of the process is increased.

The compositions of the present invention are also useful for purgingpaint residues from automated and manual equipment such as paintsprayers and paint dip installations. Typically, the concentratecomposition is introduced into a purge tank containing an amount ofdeionized water effective to dilute the concentrate composition to aconcentration of between about 5% and about 15% by volume. The resultingworking purge solution is heated to a temperature of from about 38° C.to about 54° C. and then circulated through the equipment to purge anyresidual paint from the equipment. When actually contacted with thesurfaces of the equipment containing the paint residues, the usetemperature of the working purge solution is typically about 26° C. toabout 32° C. due to heat losses during circulation. To minimize waste,the used purge solution may be reconditioned (by removing paint solidsthrough means such as filtration, settlement, coagulation or the likeand/or replenishing one or more components of the purge solution) andrecirculated through the equipment. Prior to and/or after circulation ofthe working purge solution, the equipment may be subjected to othercleaning methods such as purging with water alone or with a gas such asair or nitrogen.

The contact time needed to effect a substantial loosening of the paintfrom a surface will depend on the nature and thickness of the paint, therelative activity of the components in the composition, theconcentrations of such components, and the temperature of the solution,among other factors. With some paints and under some conditions, contacttimes of a few minutes (e.g., 2-3 minutes) may be sufficient, while withother more difficult to remove paints and with more dilute solutions orlower contact temperatures, appreciably longer contact times (e.g., upto 1 hour) may be desirable.

The invention and its benefits compared with prior art processes may befurther appreciated by consideration of the following working andcomparative examples, which are not to be understood as limiting theinvention in any way except to whatever extent conditions used in theexamples may be found in the appended claims.

Test Substrates

Static Dwell Test Substrates and Method: Thin films of waterborne paintwere applied to a glass panel and subsequently baked at 49 to 55° C. for0.5 to 4 hours. The tested working paint-removing solutions were applieddropwise to the thus prepared test panels, which were then observed todetermine the point at which the film softened or bubbled.

Spray Test Method: Thin films of waterborne paint were applied to aglass panel and subsequently baked at 49° C. for 0.5 hours. Aconventional spray gun having a 1.07 millimeter fluid tip size waspositioned 10 centimeters away from a thus prepared glass panel. Using afluid pressure as noted below for a particular instance, a solid streamof liquid was directed onto the coated glass panel until a circle ofbaked paint with a diameter of 10.4 millimeters was completely cleanedfrom the panel, and the time required was recorded. (In some instancesin comparative examples, such cleaning was not achieved within themaximum time allowed; any such instance is noted explicitly.)Temperatures are also specified below for each particular test.

WORKING AND COMPARATIVE EXAMPLE GROUP 1

In this group, the following concentrates were used to make thepaint-removing solutions used: Comparative Concentrate C1.1 consisted of98% of ethylene glycol n-butyl ether and 2% of 2-aminopropanol-1;Working Concentrate C1.2 consisted of 10% of 2-amino-propanol-1 and 90%of Harcross T Det P4™ ethoxylated phenol, which was reported by itssupplier to have the following distribution of degrees of ethoxylation,where the number of oxyethylene units per molecule is indicated by n:3.3% of n=1, 11.6% of n=2, 19.9% of n=3, 22.4% of n=4, 18.6% of n=5,12.3% of n=6, 6.7% of n=7, 3.1% of n=8, 1.26% of n=9, balance of n≧10;Comparative Concentrate C1.3 consisted of 2-aminopropanol-1 only. Theseconcentrates (when used) were diluted with deionized water to make theworking compositions shown in Table 1. All of the test substrates usedin this group were prepared with the same paint, Du Pont water-basedGalaxy Silver automobile paint, under the conditions noted above forspray testing.

TABLE 1 % of Volume of Cleaning Characteristics Concentrate % Deviationin Working Spray Average from the Observation Concen- Paint- Pressure,Seconds Number Mean, If of trate Removing Bars of of More ThanThoroughness Used Solution Absolute Spraying Tests One Test of CleaningC1.1 10  1.3 19.5 3 4.2 Clean C1.1 5 1.3 19.3 1 Clean C1.3 1 1.3 31 1Film of silver flakes left on panel None None 1.3 60 1 20% Removed, witha film of silver flakes left on panel C1.2 5 1.3 14.1 1 Clean C1.1 10 2.0 4.1 1 Clean C1.1 5 2.0 8.0 3 9.0 Clean C1.3 1 2.0 11.0 1 Film ofsilver flakes left on panel None None 2.0 60 1 60% Removed, with a filmof silver flakes left on panel C1.2 5 2.0 5.1 1 Clean C1.1 10  2.7 4.1 25.5 Clean C1.1 5 2.7 6.3 1 Clean C1.3 1 2.7 7.8 1 Film of silver flakesleft on panel None None 2.7 23 1 90% Removed, with a film of silverflakes left on panel C1.2 5 2.7 3.9 1 Clean

WORKING AND COMPARATIVE EXAMPLE GROUP 2

In this group, Du Pont Galaxy Silver, BASF Red Primer, and BASF ImolaRed Primer automobile paints were tested by spraying. WorkingConcentrate C2.1 was the same as Working Concentrate C1.2. WorkingConcentrate C2.2 consisted of 90% of ethoxylated benzyl alcohol (ST-8329from Clarient Corporation) with an average of 4 oxyethylene units permolecule and 10% of 2-amino-propanol-1. Working Paint-Removing SolutionsPRS2.1 and PRS2.2 consisted of 3.0% by volume solutions of C1.1 and C1.2respectively in deionized water, and Comparative Paint-Removing SolutionPRS2.3 was a solution of 0.3% of 2-aminopropanol-1 in deionized water.All of the working solutions were maintained at 49° C. during testing.Spray pressures and test results are shown in Table 2. These resultsindicate that ethoxylated benzyl alcohol performs equivalently to orvery slightly better than ethoxylated phenol.

TABLE 2 Working Spray Paint- Pressure, Spraying Removing So- Bars Abso-Time, Sec- Paint lution lute onds Du Pont Galaxy Silver PRS2.2 1.3  8.6Du Pont Galaxy Silver PRS2.1 1.3  9.3 Du Pont Galaxy Silver PRS2.2 2.7 2.5 Du Pont Galaxy Silver PRS2.1 2.7  2.6 BASF Red Primer PRS2.2 2.7 1.62 BASF Imola Red Primer PRS2.2 2.7  1.25 Du Pont Galaxy SilverPRS2.3 2.7  3.5* Du Pont Galaxy Silver PRS2.3 1.3 15.9* *A substantialpaint film was left on the area nominally cleaned in these comparativeexamples.

EXAMPLE AND COMPARATIVE EXAMPLE GROUP 3

In this group, the effectiveness of various alkoxylated aromaticalcohols and comparative alternatives were determined. Unless otherwisenoted, all were used to make concentrates with a 9.0:1.00 ratio betweenthe alkoxylated aromatic alcohol component or its alternate and2-amino-propanol-1, and the concentrates were diluted to 10% by volumewith deionized water to make the working or comparative flushingsolutions. All of the working flushing solutions according to theinvention were made with ethoxylated phenol, but the degree ofethoxylation was varied as shown in Table 3. The alternative substances,not according to the invention, are identified in Table 3 by thefollowing abbreviations: A1=Emphos™ TS-211 ethoxylated phenol phosphateester; A2=sodium xylene sulfonate; A3=ethylene glycol mono-n-butylether; A4=ethylene glycol mono-n-butyl ether, but with a mixing ratio to2-amino-propanol-1 of 49:1.00 instead of 9.0:1.00; andA5=2-amino-propanol-1. The paints tested, which were all commerciallyavailable water-borne automobile paints, are identified in Table 3 bythe following abbreviations: P1=PPG Silver; P2=PPG White; P3=PPG Red;P4=PPG Blue; P5=BASF Silver; and P6=Du Pont Galaxy Silver. Three dropsof the flushing solution being tested were applied to the testsubstrates prepared for static dwell testing as described above. Bakingcondition B1 was 53° C. for 4 hours; baking condition B2 was 49° C. for0.5 hour. The following abbreviations were used to indicate the effecton the paint film if it did not dissolve: S,ns=Softened, no stripping ordissolution; Nd=no dissolution. The results are shown in Table 3 andindicate that the paint-removing solutions according to the inventionwere more effective overall than any of the comparative paint-removingsolutions tested and have lower VOC than any of the comparativepaint-removing solutions A3 through A5 that have reasonably closestripping ability for some of the paints tested. The results alsoindicate that the paint removing performance of solutions containingethoxylated phenol with an average of 4 oxyethylene moieties permolecule was in most instances equivalent or superior to that ofsolutions containing ethoxylated phenol with an average of only 1oxyethylene moiety per molecule. This was surprising since it had beenexpected that the ability of the alkoxylated phenol to loosen the paintfilm would decrease as the degree of ethoxylation increased. The use ofethoxylated phenols containing a higher degree of ethoxylation is alsoadvantageous since such materials have greater water solubility andlower VOC content.

TABLE 3 Paint Time in Seconds to Bubble, Significantly Soften, orDissolve, with: and Ethoxylated Aromatic Alcohol, Alternative to BakingAverage Oxyethylene Moieties Ethoxylated Condi- per Molecule AromaticAlcohol tions 1 4 6 9 A1 A2 A3 A4 A5 P1 B1 107  24 28 34 120 S,ns 120S,ns 35 120 S,ns 41 P2 B1 21   14.6   18.9   17.2 120 S,ns 120 S,ns 13120    14.6 P3 B1 26 32 40 41 120 S,ns 120 S,ns 38 120  40 P4 B1 No test  14.6   16.7   17.4 120 S,ns 120 S,ns No test No test 21 P5 B2 29 15 2229 120 S,ns 120 S,ns 24 24 24 Nd P1 B2 15 12   16.5 29 20 Nd 24 Nd 24 2424 Nd P6 B2 22 16 26 37 120 S,ns 120 S,ns 10 21 120 S,ns

EXAMPLE AND COMPARATIVE EXAMPLE GROUP 4

In this group, a variety of ethoxylated phenols and other materials wereinvestigated for paint removal by spraying, with the paint-removingsolution at normal room temperature (about 22° C.). The paint used wasDu Pont Galaxy Silver, which had been baked at 49° C. for 0.5 hourbefore being tested. Spray pressure was also varied. Each testedmaterial was mixed in a ratio of 9.0:1.00 with 2-amino-propanol-1 toform a concentrate, except that for A 11, the ratio was 49:1.00. Workingpaint-removing solutions were made by diluting a concentrate withdeionized water to a concentration of 5% by volume of the concentrate inthe working paint-removing solution. The following alternatives foralkoxylated aromatic alcohols in accordance with the invention wereused, with short identifiers used in Table 4: A6=Triton™ X-45ethoxylated octyl phenol surfactant; A7=Tergitol™ NP-9 ethoxylated nonylphenol surfactant; A8=Neodol™ R1-5 ethoxylated alcohol surfactant;A9=Ethomeen™ C25 ethoxylated amine surfactant; A10=Merpo™ A ethoxylatedphosphate surfactant; and A11=Ethylene glycol mono-n-butyl ether.Additional specific conditions and results are shown in Table 4. Again,there was general superiority of the examples according to the inventionover the comparative examples in cleaning effectiveness, reduced VOCcontent, or both.

TABLE 4 Time in Seconds to Clear (Unless Otherwise Noted)* a Circle witha Diameter of 10.4 Millimeters with Flushing Solution Containing:Alkoxylated Aromatic Alcohol, Average Spray Oxyethylene Alternative toPressure, Moieties per Alkoxylated Bars Molecule Aromatic AlcoholAbsolute 4 6 9 A6 A7 A8 A9 A10 A11 1.30 26 40 40 40 40 40 40 40 25 NecNec Nec Nec 30% 2.7   6 13 20 40 40 40 25 40 5.6 50% 40% 10% 30% *Apercentage after the number of seconds indicates the approximate % ofthe surface that was actually cleaned when this was not all of thesurface; “Nec” means “No effective cleaning.”

EXAMPLE AND COMPARATIVE EXAMPLE GROUP 5

In this group the concentration and spray pressure were the primaryindependent variables. All of the examples according to the inventionused a concentrate that consisted of 90% of Harcross T-Det P-4™ethoxylated phenol and 10% of 2-aminopropanol-1. The nature of theworking solution in the comparative examples and other details andresults are given in Table 5 below. The test panels were prepared in thesame manner as for Group 4 and with the same paint, and the paintremoving solutions were maintained at 17° C. during the spraying. At thesame concentration, a paint-removing solution according to the inventionwas superior to an example of current commercially preferredpaint-removing solutions for this application.

TABLE 5 % of Volume of Cleaning Characteristics Concentrate % Deviationin Working Spray Average from the Observation Concen- Flush- PressureSeconds Number Mean, If of trate ing Bars of of More Than ThoroughnessUsed Solution Absolute Spraying Tests One Test of Cleaning According tothe Invention 5.0 1.3 21 3 2.3 Completely clean 5.0 2.7 5.1 1 Completelyclean 4.0 1.3 25 2 4.0 Completely clean 4.0 2.7 5.4 1 Completely clean3.0 1.3 37 2 1.9 Completely clean 3.0 2.7 6.7 2 3.0 Completely clean 2.01.3 50 1 Completely clean 2.0 2.7 8.7 2 3.1 Completely clean 1.3 1.3 581 Completely clean 1.3 2.7 14 1 Completely clean None None 1.3 120 1 Noobservable cleaning effect None 2.7 120 1 No observable cleaning effect2-Aminopropanol-1 0.50 1.3 120 1 No observable cleaning effect 1.33 2.726 1 Some of the paint was removed, but at least a thin layer was leftover the entire sprayed area 98% of ethylene glycol mono-n-butyl ether +2% of 2-aminopropanol-1 10 1.3 25 2 2.9 Completely clean 10 2.7 4.9 25.2 Completely clean 5.0 1.3 28 1 Completely clean 5.0 2.7 8.2 1Completely clean 4.0 1.3 32 1 Some of the paint was removed, but atleast a thin layer was left over the entire sprayed area 4.0 2.7 13.4 1Some of the paint was removed, but at least a thin layer was left overthe entire sprayed area 3.0 1.3 40 1 Only 30% of the paint was removed,and at least a thin layer was left over the entire sprayed area 3.0 2.720 1 Some of the paint was removed, but at least a thin layer was leftover the entire sprayed area 2.0 1.3 40 1 No observable cleaning effect2.0 2.7 34 1 Some of the paint was removed, but at least a thin layerwas left over the entire sprayed area

1. A composition useful for removing paint from a non-water-soluble surface comprising: a) water; b) a water-soluble alkoxylated aromatic alcohol containing at least two oxyalkylene moieties per molecule and an aromatic ring moiety in each molecule which does not bear any alkyl substituent having more than 4 atoms; and c) a water-soluble base comprised of: 1) an alkanolamine and 2) an alkali metal silicate in an amount of about 0.001 to about 0.1 weight percent of the composition.
 2. The composition of claim 1 wherein the alkanolamine is select from the group consisting of monoisopropanolamine, dimethylethanolamine, diethanolamine, triethanolamine, triisopropanolamine, monoethanolamine, n-butyl diethanolamine, 2-methylaminoethanol, n-butylaminoethanol, diethylaminoethanol, 2-amino-2-methyl-1 -propanol, phenyl diethanolamine, and diisopropanolamine.
 3. The composition of claim 1 wherein said water-soluble alkoxylated aromatic alcohol is selected from the group consisting of ethoxylated phenols, ethoxylated benzyl alcohols, and mixtures thereof.
 4. The composition of claim 1 wherein said water-soluble alkoxylated aromatic alcohol contains from 2 to 10 oxyethylene moieties per molecule.
 5. The composition of 1 wherein said composition comprises from about 0.5 to about 30 weight percent of said water-soluble alkoxylated aromatic alcohol.
 6. The composition of claim 1 wherein said water-soluble alkoxylated aromatic alcohol is a mixture of compounds corresponding to the general structure

wherein m represents a positive integer which is from about 3 to about 10 on average, each of R¹ -R⁴, independently for each and independently from one to another of the m Instances of each R¹ -R⁴ in the same molecule, represents either a covalently banded hydrogen atom or a covalently bonded methyl moiety, subject to the proviso that at least about 80 number % of the moieties indicated by the symbols R¹ -R⁴ in said mixture represent hydrogen atoms, Ar is a substituted or unsubstituted phenyl moiety, subject to the proviso that Ar contains no alkyl substituent containing more than 2 carbon atoms, R⁵ is selected from hydrogen or methyl, and p is 0 or
 1. 7. A composition useful for removing paint from a non-water-soluble surface comprising: a) water; b) water-soluble ethoxylated aromatic alcohol selected from the group consisting of ethoxylated phenols, ethoxylated benzyl alcohols, and mixtures thereof, wherein said ethoxylated aromatic alcohol contains an aromatic ring moiety and an average of from about 3 to about 10 oxyethylene moieties per molecule, but does not contain any alkyl substituent on said aromatic ring moiety having more than 2 carbons; and c) water-soluble alkanolamine in an amount sufficient to provide a pH of 8-14.
 8. The composition of claim 7 wherein said composition is additionally comprised of alkali metal silicate.
 9. The composition of claim 7 wherein said composition is comprised of from about 10 to about 20 weight percent water-soluble alkanolamine.
 10. The composition of claim 7 wherein water-soluble ethoxylated aromatic alcohol and water-soluble alkanolamine are present in said composition at a ratio by weight of from about 2:1 to about 30:1.
 11. A composition useful for removing paint from a non-water-soluble surface comprising; a) water; b) from about 1.0 to about 20 weight percent of water-soluble alkoxylated aromatic alcohol selected from the group consisting of ethoxylated unsubstituted phenols, ethoxylated unsubstituted benzyl alcohols, and mixtures thereof, wherein said ethoxylated aromatic alcohol contains an average of from about 3 to about 10 oxyethylene moieties per molecule; c) from about 0.1 to about 2 weight percent of water-soluble alkanolamine; wherein (b) and (c) are present In said composition in a weight ratio of from about4:1 to about20:1.
 12. The composition of claim 11 wherein said composition is additionally comprised of at least one additional component selected from the group consisting of surfactants, solvents, chelating agents, and corrosion inhibitors.
 13. The composition of claim 11 wherein said composition is additionally comprised of from about 0.001 to about 0.1 weight percent alkali metal silicate.
 14. The composition of claim 1 wherein the composition has a pH of 9.5-11.5.
 15. The composition of claim 6 wherein p is
 1. 16. A composition useful for removing paint from a non-water-soluble surface comprising: a) water; b) a water-soluble alkoxylated aromatic alcohol containing an average of from about 3 to about 10 oxyalkylene moieties per molecule and an aromatic ring moiety in each molecule which does not bear any alkyl substituent having more than 4 atoms; and c) about 10 to about 20 weight percent water-soluble alkanolamine.
 17. The composition of claim 16 wherein water-soluble ethoxylated aromatic alcohol and water-soluble alkanolamine are present in said composition at a ratio by weight of from about 2:1 to about 30:1.
 18. A composition useful for removing paint from a non-water-soluble surface comprising: a) water; b) a water-soluble alkoxylated benzyl alcohol containing at feast two oxyalkylene moieties per molecule and an aromatic ring moiety in each molecule which does not bear any alkyl substituent having more than 4 atoms; and c) a water-soluble base comprised of an alkanolamine in an amount sufficient to provide a pH of 8-14.
 19. The composition of claim 18 wherein water-soluble ethoxylated aromatic alcohol and water-soluble alkanolamine are present in said composition at a ratio by weight of from about 2:1 to about 30:1. 